Output-Constrained Robust Sliding Mode Based Nonlinear Active Suspension Control

The nonlinear active suspension control design can be analyzed as a multiobjective control problem that caters to the enhancement in ride comfort levels while ensuring that road holding is maintained with the constrained suspension displacement movement. In this article, a robust constrained output feedback approach employing sliding mode controllers is proposed for the nonlinear active suspension system equipped with hydraulic actuators. Adhering to mechanical design limitations, the suspension displacement and the corresponding displacement rate are constrained using asymmetric barrier Lyapunov functions. Consequently, a nonlinear control law that incorporates the first-order sliding mode control is then formulated to regulate the hydraulic valve and thereby provide an active control effort. The robust control performance with high-performance improvements for ride comfort in the presence of parametric uncertainties, sensor noise, and over variable driving velocities for different road conditions is established using simulation studies.